Over and under actuator for electric switches



Jan. 13, 1953 J. s. COLDWELI. 2,625,629

OVER AND UNDER ACTUATOR FOR ELECTRIC SWITCHES Filed Aug. 28, 1950 2SHEETSSHEET 1 SULAr/U/V 34 INVENTOR. Jok 72 ,8; f'aZawaZZ.

ATTORNEY Jan. 13, 1953 J. 5. COLDWELL 2,625,629

OVER AND UNDER ACTUATOR FOR ELECTRIC SWITCHES Filed Aug. 28, 1950 2SHEET$-SHEET 2 INVENTOR. J07? Sf Cldzoeil MKQ W ATTORNEY Patented Jan.13, 1953 OVER AND UNDER ACTUATOR FOR ELECTRIC SWITCHES John S. Coldwell,Milwaukee, Wis., assignor to Globe-Union Inc., Milwaukee, Wis., acorporation of Delaware Application August 28, 1950, Serial No. 181,904

'This invention relates to improvements in elec- I trical switches andparticularly to such switches of the quick-make and quick-break type.

'Switches of this type are frequently used in connection with othercontrol components, such as radio rheostats and the like, and areoperated by the same control member as such component. Heretcfore suchswitches have been added as a complete unit to the other component withan associated mechanism to form the inter-operative connection. Thecombined unit so made is comparatively bulky and expensive and noteasily used in such applications as miniature radio sets, hearing aids,and the like.

One object of this invention, therefore, is to provide a switch of thistype which may be simply and inexpensively built into another controlcom" ponent to create a small compact unit.

Quick-make and quick-break actions have been accomplished by togglemechanisms, hill and valley constructions, ball and detent mechanisms,

garter springs, and other like devices. Each type is particularlyadapted for a special application. Most of them are complicated andcostly to make. Some of them do not have true snap action, slowoperation of the control member eliminating the snap action.

Another object of this invention, therefore, is to provide a switch ofthis type which: has positive and reliable quick-make and quick-breakaction no matter how slowly the control shaft is operated; may beutilized for both single and multiple pole and throw; and may beoperated by either angular or linear motion of a control mem ber. i

In accomplishing the foregoing objects, a spring contact having aninsulator-striking block is moved from a normally biased position(either switch closed or open) to a controlled position (either switchopen or closed) by the force of a spring-actuator engaging such block.The application of the force of the spring-actuator is controlled by themovement of such actuator relative to a fixed cam. As the actuator movesei ther into or out of juxtaposition with respect to such block the camflexes the actuator out of its normal position so that upon release fromthe cam the actuator snaps either against or away from such block toquickly move the spring contact with a snap action. In one direction oftravel of the actuator it will move over said cam and. in the oppositedirection of travel it will move under said cam to effect the desiredquick application or quick withdrawal of actuating force. This principleof quickly applying and re- '11 Claims. (Cl. 200-154) gaeement withfixed contacts.

or make of switch contact.

moving a force to and from the spring contact may be utilized in variousways. The spring contact may carry one or a multiplicity of contacts. Itmay be biased either into or out of en- It may be normally in contactwith one set of contacts and biased into contact with another set ofcontacts. Thus a single or multiple pole or single and -double throwswitching action may be obtained. No matter how slowly the controlmember moves the actuator the release of the latter from the cam isalways instantaneous and complete so that the stored force is suddenlyapplied or removed to provide a sure and dependable snap action breakThe length of engagement between cam and actuator is relatively short sothat only a minimum movement of the actuator is required to effectswitching action. The actuator may be carried by a movable ele- *nent ofthe other control component, the fixed cam may be positioned on thehousing of such component, and the fixed contacts and spring contactsmounted on the cover for such housing. Thus a relatively small number ofparts is em- 'oloyed and such parts incorporated with the elemerits ofthe other control component to make a compact inexpensive unit. As anytype of relative movement between cam and actuator will control suchactuator the movement of the control member may be linear or angularthus making the switch applicable for use with a large variety of othercomponents. However, a switch embodying these principles may beconstructed and used as a separate individual unit.

The novel features which are considered char acteristic of the inventionare set forth with particularity in the app-ended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional objects and advantages thereof, willbest be understood from the following description of a specificembodiment when read in connection with the accompanying drawings, inwhich:

Fig. l is a View partly in elevation and partly in cross section on themeandering section line |l in Fig. 2 of a switch embodying the presentinvention incorporated with a variable resistor,

in the position assumed as the switch is being actuated toward onposition;

Fig. 5 is a view similar to Fig. 3 with such parts shown with the switchin on position;

Fig. 6 is a view similar to Fig. 3 with such parts shown as the switchis being actuated toward 01? position;

Fig. 7 Ba top plan View of another modification of the switch embodyingthe present invention and operated by lineal movement of the controlmember; and

Fig. 8 is a view in side elevation of the .switch viewed in Fig. '7.

In Figs. 1 to 6, inclusive, theswitch embodying the present invention iscombinedwith another control component such as a variable resistor. Asthe variable resistor. is. of well-known construction it will not befully described herein. The switch and variable resistor are mounted-ina metal shell or case ld'to which is secured a mountingbushing 5'2rotatably carrying a control member .orshaft 5- 3.Thevariablerresistonis adjusted by-therotation of-such control member asit 'movesp'an insula-ted-rcontact shoe 4,6 stakedto the inner endthereof. The variable resistorlshas customary electrical terminals, oneof"which,isindicatedat l8. Thecontact shoe l6,'together with theinnerend of-shaft 1 3, comprise the mounting support for aspring-actuator 2D staked con and rotatable -with*such shaft. A camfollower-22 carried by the'spring-actuator 20 is biased thereby'to aneutral position spaced laterally from the "body of-suchspring-actuator.The follower 22 may thusbe flexed to either side of its neutralposition. enough so that the follower while in substantially'neutralposition will be able to assert enoughforce to counteractthe inherentforce in the rspring contact. Because of the inherent characteristics ofthe variable resistor :there .is oneportion of the totalmovementof'theshaft l 4 :at which. it is desirable to accomplishswitchingoperation. A fixedcam 24 is stationed near such portion in the normalpath of travelf the'follower '22 to engage'the follower and cooperate ineiiectingswitch operation. The cam 2d may be made, as is shown inFigs.1'.and'2,.by cuttingand' forming out a portionofthewall of the housingIii, or any other way of so'fixedly positioning thecam in the path' ofthe 'follower will be satisfactory. It is only essential thatthefollower bemomentarily flexed fromnormal position and suddenly.releasedso thattheforce so stored therein by suchflexingcan beutilizedto open or close the: switch contact. In theparticular embodiment shownin .Figs. 1 to 6, .the cam 24 is sloped rearwardly and upwardly (asviewed inzF-ig. 1). As viewed in Figs..3. to 6,:inclusive,up"is down'.onthe sheet, top is bottom on the sheet,*and vice versa, because suchviews were'taken on-a-sectional viewof Fig. 2 and Fig.2 'is-an invertedview. I-Iencepas the follower 22 is "moved angularly clockwise .(asviewed inFig. 2) from-the switch oif position shown in Fig. 2'it willstrike against thetop of the cam z'andbe flexed upwardly. When thefollower gz'clears the upper edge of thecam 24 it will forcibly springto its normal .unfiexed position. When the follower 22 isreturnedangularly counterclockwise it will engage the bottom ofcam 24 and beflexed downwardly until-it clears the lower edge of such cam. Thefollower willthen again spring to its normal unflexed position.

.The controlled. movement :ofthe follower. 22: is

The actuator is stiff used to operate a spring contact 26 mounted withinthe casing ID on a terminal 28. In this embodiment spring contact 26 isinherently biased toward engagement with a fixed contact 30 also mountedwithin the casing It by a terminal 32. However, the inherent force inthe spring contact "26 is HOt-"SIlmCiGHttO "overcome the inherentstiffness-in spring-actuator 20'and cause it to have any substantialmovement from normal position. Operative engagement between the follower22 and the spring contact 25 is accomplishedthroughan insulating block34 secured to the'end'of the spring contact 2'5 by suitable means.An-example of such means consists of a p'ortion'saticutfrom the body ofthe spring contact ilfi and bentitoward the end of such spring contactso as topass through an opening in the block as. The end'of such portionis clinched againsti'thelblock to hold it in place, as shown. The width(vertical dimension as viewed in Figs. 3 to-;6) -of the-blockiszsuihcient-so that when itis engaged by thefollower 22 the spring:contact 26 will be raised fromengagement with fixed contactSi]. This isthe position shown inFigsal,

.2, and 3. In order to permit thefollowerZZ-to be fiexedupwardly by thecam. 24 without letting the. spring-actuator 26 make .contact with .thefixedcontact .36, alower corner of theblock-34 is out ofi, as indicatedat'33, to provide a sloping :edge substantially .parallel with .thesurfaceof the canrz l. Thus as the follower22 is moved clockwise, asviewed inFig. 2, and engageson the top of cam .24, it will slideupwardly along the sloping surface 38 atthesame-ratethatit*slidesupwardlyalong the cam 24. This'relationship, as shown in Fig. 4,will notpermit the block 34 to change its position until .the follower22 leaves the cam-24. When .the 'follower leaves the cam .24... andsprings.to;its normal position, the inherent resilience. in .the springcontact. 26 will. cause. it .tosnap. to .theclosed or on positionofj'ig.5. :Thespring-actuator-20- is then free to move with the control memberI 4 :as it regulates. or operates the other component. :Uponreversemovement of the member I l-the follower 22 will..ride. down. thebottom of thecam- 24' (see Fig. 6) and not contact the block until .itclears the end of.such cam. Atsuchtime the followerwillriseand strikethe spring arm 22.breaking the .contact with asnap.

In. Figs. 7 and Bthere is shown -a-modification in which the switchembodying-.thepresent. inventionis. not. combined with any. othercontrol component. .In this modification theswitching action resultsfrom a lineal movement of the control member. The controlmemberconstitutes a push bar 46 whichis slidably smountedin-=a pair-of.spaced bracketsJi i and- 36 carried..by.-.a frame .42. .A leg .48 .onsuch .framedorms the supportjoran insulating platefiii. on whichismounted the switch contacts. The fixed contact 52 iscarried on abracket54 so as'to bespace'd from .the plate. A terminal t5 issecured to suchbracket. Thespring contact 58. is secured-tothe plate'fiii and underliesthe fixedcontact 52being biased soastobe normally in engagementtherewith. .Aterminalfiilis connected with the spring contacted Thespringcontact '58 is1snapped open in a manner similar .to thatpreviouslydescribedi-n connection with therfirstmodification by thecontrolledaction of a springeactuator 52 .mounted on the-push'bar as.'This'springactuatorhas'a'cam follower 6 3 in linealialinement'with afixed cam. 86 carried on the frame 42. The spring :contact- .58 carriesan insulating block 68 with a sloping edge 1!! substantially parallel toand slightly spaced from the cam 66 in the normal position as shown inFig. 8. When the push bar 46 is moved in a lineal path inwardly or tothe right as viewed in the figures, the follower 65 will ride up on thcam 65 and bias the spring-actuator 52 from its normal position. Whenthe follower 84 clears the cam 66 the actuator 62 will cause it tospring down on the top of the block 68 and snap the contacts to openposition. When in this position lineal movement of the push bar as tothe left will cause the follower 64 to ride down the underside of cam66. During such movement the follower will be in engagement with thesloping surface and thus still' keep the contacts open. However, whenthe follower 64 clears the cam 66 it will spring to its normal positionshown in Fig. 8 permitting the contacts to snap closed.

The principle herein described of actuating single pole throw switchescan also be used to operate multiple pole single throw switches ormultiple pole double throw switches. The switches may be operated fromeither normally open to closed or normally closed to open positions. Anynumber of fixed contacts may be employed and engaged by a number ofmovable contacts operated by a single actuator. In the case of a doublethrow switch the fixed contacts are positioned on opposite sides of thespring contact member. In both the modifications disclosed herein, thefollower, the fixed cam, and the insulating block all have slopingsurfaces which are substantially parallel. lhe purpose of this is toprovide smoother action. However, as previously explained, the essenceof the invention is to momentarily force the spring-actuator out of anormal position. This may be done by a follower which is sloped and afixed cam which is not sloped at all. The same result may b accomplishedby a follower which has no slope and a a cam which has the desiredslope. It is not necessary in all cases to provide a sloping surface onthe striker block except to provide necessary clearance to permit thespring contact to go to completely normally closed position. It does notmake any difference in the desired switching action if the springcontact is moved farther away from off position during the returnmovement of the spring-actuator.

Although only several embodiments of the invention are shown anddescribed herein, it will 'be understood that this application isintended to cover such other changes or modifications as come within thespirit of the invention or scope of the following claims.

I claim:

1. In an electric switch having relatively movof said contacts tocontrol the movement of said contacts, and cam means in said path forflexing said actuator from said normal path, said actuator upon releasefrom said cam means controlling the movement of said contacts with asnap action.

2. An electric switch as claimed in claim 1 in which said actuator ridesup and snaps down from said cam means in one direction of travel andrides under and snaps up from said cam means in the opposite directionof travel to effectuate operation of said contacts.

3. In an electric switch having relatively movable contacts, one of saidcontacts having an actuator engaging portion, a spring actuator hav- 6ing a normal path of travel in alinement with said portion, an actuatorflexing member in said path, and camming means operative between saidmember and said actuator to temporarily flex said actuator out of saidpath and suddenly release said actuator for return to said path while injuxtaposition with said portion to operate said contacts.

4. An electric switch as claimed in claim 3 in which said portion andsaid camming means have related sloping surfaces permitting saidactuator to be flexed while traveling from said portion toward saidmember without operating said contacts.

5. An electric switch including a spring contact biased toward oneposition, a relatively stiff member having a normal place in which saidmember holds said spring contact away from said one position, cam meansfor temporarily deflecting said member from said normal place andpermitting said member to snap back to said normal place upon release ofsaid cam means consisting of a flat sloped camming surface and a movablefollower one of which is relatively fixed and the other of which ismoved by a control member, and a control member for said cam means.

6. An electric switch including a spring contact biased toward oneposition, a relatively stiff member having a normal place in which saidmember holds said spring contact away from said one position, cam meansfor temporarily deflecting said member from said normal place andpermitting said member to snap back to said normal place upon release ofsaid cam means consisting of upper and lower fiat sloped cammingsurfaces and a movable follower, one of said follower or said surfacesbeing relatively fixed and the other being movable by a control member,and a control member for said cam means, said follower riding up saidupper surface in one direction of movement of said control member andriding down said lower surface in the opposite return direction ofmovement of said control member.

7. An electric switch as claimed in claim 5 in which said control memberconsists of a rotating shaft.

8. An electric switch as claimed in claim 5 in which said control memberconsists of a slidable bar.

9. An electric switch comprising relatively movable contacts, a rotatingmember movable in a normal path to actuate the contacts, a stationaryobstruction in said path, said member riding over one side of saidobstruction and being deflected from its normal path and snapping backto its normal path as it leaves said obstruction when operated in onedirection, said member riding over the other side of the obstruction andbeing deflected in the opposite direction from its normal path andsnapping back to its normal path as it leaves said obstruction whenoperated in the opposite direction, the snap in opposite directions asit passes alternate ends of said obstruction operating said contacts.

10. An electric switch having relatively movable contacts, an actuatingmember consisting of a flat spring, a flat cam in the path of saidspring and set at an angle to said path so that said spring engages andrides over one side of the cam when it approaches it from one directionand engages and rides over the opposite Side of the cam when itapproaches from the opposite direction, departure from the cam at eachend effecting movement of said switch contacts.

11. In an electric switch having movable con- 7 tacts, a movable.-actuating member, a stationary cam .for temporarily biasing -saidmemher, :a striker block ,on .one. of :.said contacts having ."a portionbeneath said :cam engageable .by said member as said membersnaps offsaidocam in one direction of travel thereof tooperate'said contacts,said block having -a 'taperalong which said member slides in the returnopposite direction of travel so that as saidmember is biased byrsaid camsaid block Will not be moved sufiiciently to operate said contacts untilsaid member-clears'said cam.

JOHNS. COLDWELL.

8 .REEERENCES CITED 'The"fo11owing references are of x.record:.ini'thefile'ofthis patent:

UNITED STATES PATENTS Number Name 'Date 2,014,474 Hopkins Sept. 17,19352,431,197 Platt Nov. 18, .1947

FOREIGN PATENTS Number Country Date #396,270 Germany May 31, 1924

